The optical transport network (OTN, Optical Transport Network) technology is a new optical transport technology, which is capable of implementing flexible scheduling and management of high-capacity services, and already becomes a mainstream technology of a backbone transport network currently.
Three signal types are defined in the existing OTN: an optical channel data unit 1 (ODU1, Optical Channel Data Unit 1), an ODU2, and an ODU3, which respectively include 1, 4, and 16 tributary slots, and the types of the tributary slots are all 2.5 Gb/s. During the data transmission of the optical network, multiplexing or mapping relationships of related transport units are involved, so that when a transmission path is being established, it is required to designate how an ODUj is multiplexed to an ODUk (j<k), or how the ODUj is mapped to an optical channel transport unit OTUk (Optical Channel Transport Unit) (j=k). In the prior art, a method for assigning labels for neighboring nodes is usually adopted to designate the multiplexing or mapping relationships. An ODU label is disclosed in the prior art, which mainly includes: a t1 field, a t2 field, and a t3 field, so different signal types, for example, an ODU1 signal, an ODU2 signal or an ODU3 signal, are denoted through different values of the t1 field, the t2 field, and the t3 field, and a tributary slot occupied during multiplexing is denoted.
During the research and implementation of the method, the inventors of the present invention find that:
Currently, new ODU signal types, such as an ODU0 suitable for transporting low-rate signals, an ODU4 suitable for transport at a higher rate, and an ODU2e, an ODU3e1, an ODU3e2, and a bandwidth-variable ODUflex, are proposed in the industry. In addition, a new tributary slot type with the bandwidth 1.25 Gb/s is further proposed. However, in the prior art, the label only supports the three signal types: the ODU1, the ODU2, and the ODU3, and at the same time only supports a tributary slot type of 2.5 Gb/s. Also, the label in the prior art has poor expandability and is unable to support new signal types and tributary slot types by extension. Therefore, the prior art is unable to assign a label in an OTN network that supports new signal types and tributary slot types.